[flypa38]

Yeah I know.....this is gonna be tough without being nearby to hear it.
My '72 TR6C is starting to make a weird noise and its getting progressively worse! It sounds like something is pinging off the exhaust at the top by the primary side pipe where it enters the head. Either its worse when sitting still, or I can't hear it over the engine noise above idle. Can't tell if its internal or something loose somewhere, but the noise doesn't always correspond to engine RPM.....leads me to believe something is vibrating somewhere. I've been all over that area outside the engine and all seems secure. So far I've checked primary chain tension and clutch adjuster locking nut and both are ok (clutch nut seems close to insp. plug, but neither is shiny indicating contact). Airplanes are loud so my ears aren't so great anymore. I sure could use some tips to locate the source of the noise!
Thanks!
Johnny

 

[Scavenger]

When you ride , does the noise get faster or louder with acceleration ?

 

[dfauerbach]

maybe the exhaust spigot is loose?? if it is get to it before it destroys the threads in the head

 

[flypa38]

When you ride , does the noise get faster or louder with acceleration ?

It changes, but doesn't match the engine RPM's changing. Kinda like the frequency of whatever is shaking is increasing but not at the same rate as engine rpm's......hope you know what I mean.

maybe the exhaust spigot is loose?? if it is get to it before it destroys the threads in the head

Too late! Maybe loose, but threads are already gone. I'm running oversized spigots.

 

[Jack Adams]

Could be a loose(in the head) valve guide. Jack

 

[SpeedAndNoise]

Take a large screwdriver and press the handle end against the center of your ear, then poke around the running engine with the other end. It's like a stethascope, and may help you find out exactly where the noise is coming from.

 

[Bodyworx]

Take a large screwdriver and press the handle end against the center of your ear, then poke around the running engine with the other end. It's like a stethascope, and may help you find out exactly where the noise is coming from.

+1 on that. Also, i have a similar noise on mine. Mine only seem to do it when the bike is leaning to the right. When i lean it to the left it goes away. See if it does it depending on position. Your description is almost identical to mine. If i find out ill let you know. Not trying to hi-jack.

 

[jakespade77]

Used the screwdriver thing before and it works, there are also mechanics stethescopes you can get that have a metal rod rather than the pad and it works better.

Do you have somebody with some bike experience to come over and listen to it too? some times 2 sets of ears is better than one...

 

['59]

have a good look 'round it mebe something simple .

i thought my / the same motor, ws pinking.
noise under load but not when blipped at lights. turned out the screw coller on the drive to the speedo had vibrated loose and the internal cable was 'jumping' about at high speed.

whatever, in your case if it ain't obvious i'd start pulling it down until i saw sign of wear indicating cause before things get expensive.

 

[Rob Axel]

I had a high pitched "ping' at one point, holed a piston shortly after. attributed it to either running lean (possible leak on one intake) or timing (points)....
The noise was heard while constant speed 55-60, not so much during acceleration idle

 

[flypa38]

maybe the exhaust spigot is loose?? if it is get to it before it destroys the threads in the head

You, sir, are the winner.......

So the oversized spigot worked loose. Fought with the pipe to work it loose from the spigot a while. Pretty sure that means it didn't un-thread!
Anyhow, I put some more Rock-Set on it and screwed it in as tight as I think I can get it before it strips out. It's a temporary fix at best.
So what are my options? I've seen the weld in spigots but can't afford that right now, I've seen holes drilled through the head and hardware used, and something else I can't remember. What are my options and pros and cons for each?
The engine is a '72 TR6C. What years interchange for cyl. heads?
Thanks!
Johnny

 

[Drew71]

So the oversized spigot worked loose. Johnny

Can I ask if these were the VW Alley ones that cut a thread ?, or the UK ones with an oversize OD on the thread 010, 020 " etc ....

Personally, I've had bad luck with weld in and drilling and fitting a fastener, welding makes the head soft & the one time I tried a grub screw the head ended up cracking.

I'd look for another head or get it machined.

 

['59]

cheapest / quickest fix (read: bodge but recoverable) spot tig to hold in place and pipe paste to seal.

 

[flypa38]

Can I ask if these were the VW Alley ones that cut a thread ?, or the UK ones with an oversize OD on the thread 010, 020 " etc .....

They were the ones that were supposed to cut threads. I think my threads were too far gone on that side to have anything to cut into.

Any details on the spot weld thing? Pretty sure the head is cast aluminum and the spigot is steel. How would that weld work?
What about brazing? Not too familiar with what can be brazed, but I have torches and oxy/acetylene.

 

[Drew71]

google HTS-2000, you can use that with a torch or Oxy, you could use that to build up the area of the thread, would still have to cut a thread though, cant braze or solder steel to aluminium.
I've never heard of welding steel to cast aluminium, I'm interested to know more too.

 

[Rob Axel]

That looks like the Alumi-weld rods Harbor freight sells...

It shows it being used in aluminum head repair....I am curious how this will hold up in the combustion chambers and exhaust area of a air cool motor?
Has anyone had any first hand experience with this stuff?
I am gonna pick some up for my oil tank...it has some tears and major stress cracks..it will be used to seal the tank..
From what I can tell the only problem is working with the stuff if heat has to be re applied...it liquifies easily... What is the temp of the head and exhaust area of these motors and what is the melting point of this stuff??

 

[Drew71]

I've used it on a thermostat housing, was easy to use and worked fine for that, drilled and tapped nicely.

The melting point is about 700 degrees, if your combustion chamber is getting anywhere near that you probably have more serious issues than the repair melting

 

[Rob Axel]

so would you consider using this for this type of exhaust spigot repair?
has anyone used this stuff for head repair???

 

[Drew71]

so would you consider using this for this type of exhaust spigot repair?
has anyone used this stuff for head repair???

Personally I wouldn't. (I would for broken fins and elongated 9th bolt hole)
I figure if you have gone down the oversize spigot path and they have failed then its time to source another one, or look into a professional repair.

I know of one machinist (who is kind of infamous on this forum) who won't weld them anymore because of too many failures. he only machines now & fabs up larger spigots

Cheers

Drew